Algar Zambujo

The pothole is a karst cavity of the vadose shaft type (Baroñ, 2003), whose genesis is due to the water that seeps deep into the epicarst and, being sufficiently acidic, causes the limestone to corrode, widening the fractures in the massif and forming the wells. It can be reached via two entrances, which are not very wide, by descending 14 m by rope to a ramp of loose stones. Descending the ramp, there is another 8 m descent, from where progress is made subvertically to an average depth of -32 m. Halfway down this diaclase (rock fracture), visitors reach the maximum depth of -45 m, down a narrow 8 m well, followed by another 3 m well. Some of the walls of the initial well present not very crystalline stalactitic layers, unlike the following and the gallery, which exhibits considerably more crystalline concretions on the ceilings, walls and floor.